Machine for the aseptic treatment of containers in bottling plant

ABSTRACT

Machine for the aseptic treatment of containers ( 10 ) in bottling plant, of the rotary type provided with a plurality of stations ( 9 ) for treating the containers and so shaped as to cause the treatment of the containers to take place under substantially sterile conditions, is characterised in that it comprises sealing means that separate a non sterile area ( 11 ) of the machine from an area ( 12 ) maintained under sterile conditions and in which the treated containers ( 10 ) transit, said means comprising a fixed annular channel ( 15 ) at least partially filled with liquid in which slides a concentric annular element ( 16 ) associated with the rotating part ( 11 ).

TECHNICAL FIELD AND BACKGROUND ART

The present invention relates to a machine for the aseptic treatment ofcontainers in bottling plant.

In plants for bottling and packaging containers for drinks (e.g.bottles) under aseptic conditions, to prevent contamination thecontainer treatment area (for instance in the steriliser, rinsingmachine, filling machine, capping machine) must be duly isolated fromthe exterior environment and maintained sterile.

According to a first constructive solution, the various machines of theplant (e.g. steriliser, rinsing machine, filling machine, cappingmachine) are totally inserted inside voluminous aseptic chambers kept inoverpressure conditions relative to the exterior environment by usingfans to inject air filtered by absolute filters, which then has aunidirectional outward flow in correspondence with the openings requiredfor the entry/exit of the containers into/from the chambers in which themachines and the components of the plant are inserted. In this way, thepossible entrance of micro-organisms into the container treatment areais prevented.

However, since the dimensions of the machines, which are generallyrotary, are considerable, the dimensions of the aseptic chambers are solarge as to make it difficult to manage them and to maintain sterileconditions.

According to another solution, to reduce the size of the chambers, onlythe process areas of the machines are isolated, leaving the remainingpart of the machines in an uncontrolled atmosphere.

In rotary machines, the process area to be isolated is defined between arotating part and a fixed part, and a barrier is required between therotating part, in which the process organs are mounted (for instance thesterilising nozzles of a steriliser, or the filling valves of a fillingmachine, or the closing heads of a capping machine, . . . ) and thefixed walls, such as the protective casing towards the exterior of themachine or towards the transmission organs.

For this purpose, gaskets made of elastomeric material have been used,generally applied to the rotating part, which slide on the normallymetallic fixed part.

Considering that the main conditions of reliability of the solution(smooth, hard sliding surface with low friction coefficient and parallelto the gasket; low sliding speeds) contrast with the considerabledimensions of the machines that prevent, due to the required workprocess tolerances and production rates, the achievement of theseconditions, it is readily apparent that the main drawbacks of thissolution are due to the rapid wear of the gasket with consequent loss ofseal.

Another known solution provides for the use of labyrinth seals, whichovercome the gasket wear problems because they do not imply any physicalcontact between the parts in relative motion.

However, the quality of the seal depends on the distance between themoving parts: as said distance decreases, seal quality increases, butachieving reduced distances (i.e. tens of millimetres) is particularlycomplex and costly in such large machines because the tolerances of themechanical work processes are such as to make it difficult to attainsuch small distances.

With this solution, moreover, another possible path for the exchange ofair with the exterior environment is given by the labyrinth seals andtherefore, to obtain an adequate overpressure a greater flow rate ofsterile air is necessary, with higher costs and with the danger of alack of isolation.

DISCLOSURE OF THE INVENTION

The aim of the present invention is to eliminate the aforesaiddrawbacks, making available a machine for treating containers in whichthe container treatment area is isolated from the exterior environmentin an extremely simple and economical manner.

Said aims are fully achieved by the machine of the present invention,which is characterised by the content of the claims set out below and inparticular in that it comprises sealing means that separate a (generallyrotating) non sterile part of the machine from a (normally fixed) partmaintained under sterile conditions and in which the treated containerstransit.

Said means comprise a fixed annular channel, at least partly filled withliquid in which a concentric annular element, associated to the rotatingpart, slides.

The sealing means substantially embody a trap.

The fixed part in which the containers are treated is maintained inoverpressure with respect to the exterior environment.

Preferably, a channel is present for each level of the machine in whichsealing means are needed and each channel preferably has an overflowdevice through which any excess liquid is eliminated, and an alarmdevice connected to a central control unit which, when the measuredlevel of liquid in the channel is lower than a pre-set threshold,activates the injection of additional liquid into the involved channel.

In correspondence with the container entry and/or exit area in therotary part of the machine, the interruption of a bed or sterilecontainer transport apparatus may be provided, so that it is split intwo and completely separated into entry transport apparatus and exittransport apparatus to make said entry and/or exit area accessible.

BEST MODE FOR CARRYING OUT OF THE INVENTION

This and other characteristics shall become more readily apparent fromthe following description of a preferred embodiment illustrated, purelyby way of non limiting example in the accompanying drawing tables, inwhich:

FIG. 1 schematically shows a plan view of a bottling plant;

FIG. 2 shows the filling machine—capping machine set in greater detail;

FIG. 3 shows the section A-B of FIG. 2 relating to the filling machine;

FIG. 4 shows the section C-D of FIG. 2 relating to the star conveyorbetween the filling machine and the capping machine;

FIG. 5 shows a detail of the sealing means and of the central controlunit that controls the liquid in the sealing channels.

With reference to the figures, the reference number 1 globally indicatesan aseptic bottling plant comprising a sterilising machine 2 (forinstance of the type that operates by spraying sterilising solutions), arinsing machine 3, a filling machine 4 and lastly a capping machine 5,all or the rotary type.

The containers 10 to be treated arrive at the aforesaid machines bymeans of entry star conveyors 6 a and exit therefrom by means of exitstar conveyors 6 b, which are housed in transport apparatuses or beds 7which are sterile because they are subjected to overpressure conditionswith respect to the exterior environment.

Said beds comprise a support base that normally contains themotorisation and the components not under sterile conditions, andsupports a tunnel in overpressure conditions within which are thetransport elements under sterile conditions.

Originally, the bed 7 is split in two and completely separated incorrespondence with the entry/exit area of the rotating part of themachine to create an area 8 accessible to operators, having a width ofabout 0.5-1.5 m.

With particular reference to FIGS. 2 and 3, a rotary filling machine 4is illustrated therein, provided with a plurality of stations 9 for thetreatment of the containers 10, consisting of filling valves equallyspaced on a circumference.

Tangential to the circumference, and synchronised with the rotatingplatform of the filling machine, are the two start conveyors: the entryconveyor (6 a) for the empty containers and the exit conveyor (6 b) forthe full containers.

The environment for the treatment or processing of the containers, inthe specific case the environment for their filling, is isolated fromthe exterior environment but allows the entry of the empty containersand the exit of the full containers through appropriate openings, notshown herein, in the walls that circumscribe the aseptic area.

The reference number 11 indicates a non sterile area of the machine(which oftentimes is a rotating part), whereas the number 12 indicatesan area under sterile conditions (which oftentimes is a fixed part) inwhich the treated containers 10 transit.

The part 12 is maintained under sterile conditions as a consequence ofan overpressure created in said environment by the insertion of air, fedby conduits 13 through absolute filters 14.

The seal between the non sterile area 11 and the sterile area 12 isoriginally achieved by means of a fixed annular channel 15 partiallyfilled with a liquid, in which slides a concentric annular element 16associated in watertight fashion to the rotating part.

The annular element 16 is partly immersed in the liquid of the channeland moves within the channel driven by the rotation of the machine.

The liquid, which preferably is a sterilising liquid able to eliminatethe presence of any bacteria, for instance a water and chlorinesolution, acts as an isolator preventing contact between the sterilearea and the exterior environment.

Obviously, a channel 15 is present with the respective annular element16 for each border area between the sterile area and the non sterilearea.

Because of the slight overpressure (a few millibar) inside the sterilearea 12 or aseptic chamber, a height difference 17 (of a few mm of watercolumn and equal to the overpressure created) is formed the liquidpresent in the channel 15 situated in contact with the aseptic chamberand the one situated externally to the annular element 16 in contactwith the exterior environment.

FIG. 4 shows the application of the channels 15 to the capping machine 5(shown in half section). The figure shows the use of two channels 15 atdifferent levels.

To assure the constant presence of liquid in each channels, a levelcontrol system is provided.

Said system, shown in FIG. 5, preferably comprises a single centralcontrol unit 18 and, for each channel, a probe 19 for measuring thelevel immersed in a cup 21 and a regulating valve 20 able to recalladditional liquid from a tank, not shown herein, as well as an overflowpipe 22 inserted in the cup and able to allow an automatic outflow ofthe liquid if a pre-set level (determined by the placement of the pipeitself) is exceeded, to prevent the liquid from spilling inside theaseptic chamber.

In essence, when the level measured by the probe 19 in the cup 21 islower than a pre-set minimum level, the central control unit controlsthe inflow of additional liquid into the cup. There is a cup for eachchannel level, or there may be multiple channels 15 connected to asingle cup provided said channels are located at the same height levelfrom the ground.

With the present invention, a perfect seal is obtained between asepticenvironment and exterior environment, with sealing means 15, 16, whichsubstantially embody a trap, non subject to wear and with less usage ofair than labyrinth seals.

Moreover, the seal is assured regardless of the quality of themechanical work processes, hence particular and costly working processesare not required for the parts involved with the hermetic seal of theaseptic area.

With the present solution, the only paths for the escape of sterile airfrom the system, which are inevitable, are only from the doors for theentry and exit of the containers, guaranteeing a more effective controlover the conditions of sterility of the system with less usage ofsterile air.

The present invention can be applied to any machine included in abottling plant, such as a sterilising machine, rinsing machine, fillingmachine, capsulating/capping machine.

1. Machine for the aseptic treatment of containers (10) in bottlingplant, of the rotary type provided with a plurality of stations (9) fortreating the containers and so shaped as to cause the treatment of thecontainers to take place under substantially sterile conditions, havingsealing means that separate a non sterile area (11) of the machine froman area (12) maintained under sterile conditions and in which thetreated containers (10) transit, said means comprising a fixed annularchannel (15) at least partially filled with liquid in which slides aconcentric annular element (16) associated with the rotating part (11),characterised in that a level control apparatus is provided to assurethe constant presence of liquid in each channel.
 2. Machine as claimedin claim 1, wherein the liquid is sterile liquid, such as a solution ofwater with sterilising substances.
 3. Machine as claimed in claim 1,wherein said sealing means embody as trap.
 4. Machine as claimed inclaim 1, wherein the sterile area (12) is maintained in overpressurewith respect to the exterior environment by the insertion of sterile airthrough absolute filters (14).
 5. Machine as claimed in claim 1, whereina channel (15) is present for each level of the machine in which sealingmeans are required.
 6. Machine as claimed in claim 1, wherein eachchannel (15) has an overflow device (22) through which excess liquid iseliminated.
 7. Machine as claimed in claim 1, wherein the apparatuscomprises a level probe (19) for each channel (15) connected to acentral control unit (18) which, when a liquid level below a pre-setthreshold is measured in the channel, activates the injection ofadditional liquid into the involved channel.
 8. Machine as claimed inclaim 1, wherein in correspondence with the container entry and/or exitarea a sterile bed or container transport apparatus (7) is interrupted,thereby being split into an entry transport apparatus and an exittransport apparatus with the definition of an area of accessibility (8)to the entry and/or exit area of the rotating part of the machine. 9.Machine as claimed in claim 1, wherein the sterile area (12) is a fixedpart of the machine, whilst the non sterile area (11) is a rotating partof the machine.
 10. Machine as claimed in claim 8, wherein the area ofaccessibility (8) has a width of 0.5-1.5 m.
 11. Machine as claimed inclaim 1, wherein an overflow pipe (22) allows an automatic outflow ofthe liquid if a pre-set level is exceeded.